1. Field of the Invention
The present invention relates to an improved, implantable sphincter prosthesis system for treatment of high-grade stool incontinence, which may be implanted in a space-saving way around the anal channel due to its highly integrated conception.
2. Description of the Prior Art
The currently clinically relevant Acticon Neosphincter, which is described in the literature, for treating high-grade stool incontinence comprises three separate functional components to be implanted in different anatomical areas: an inflatable ring to be adjusted around the intestine like a collar, which compresses the anal channel, a separate pressure accumulator for the compression medium, and a unidirectional pump, which connects the two components and pumps the compression medium out of the compression collar back into the pressure accumulator (Wong W D, et al., Disease of Colon and Rectum 2002, 9:1139-1153). The configuration of the functional components requires complex surgery and results in complication and explantation rates around 40%. A more compact muscle closing device, in which a change of the viscosity and density of a colloidal magnetorheological liquid is exploited for the compression procedure (U.S. Pat. No. 5,509,888), is without clinical relevance up to this point. Various devices comprising multiple seal elements which move peristaltically for closing an end of the intestine (DE 100 23 634 C2; DE 197 32 92 A1) are not usable in the area of the anal channel and thus differ significantly from the present invention, as do the systems for closing the urethra (DE 90 10 783 U1; EP 02 02 815 A2; EP 03 48 114 A1) known from urology.
Furthermore, the compression collars described in the literature are highly elastic inflatable bodies, which are essentially subject to an expansion in the scope of the inflation or deflation (balloon principle). Achieving a circular, symmetrical, and efficient lumen compression using extremely small volumes against high pressures, as may occur in the scope of efficient continence compression in the area of the anal channel, is subjected to narrow limits because of the strong deformation of the inflatable bodies. In addition, the high pressure gradient already existing at the beginning in the inflatable bodies influences the performance spectrum of a micropump, which is employed, extremely negatively during the inflation.